fix flakiness in test-debuglet.js (#207)

* A setTimeout that doesn't dominate the async done() path causes
  flakiness.
* Improve the test to be more on-topic.

src/agent/debuglet.js

@@ -52,6 +52,7 @@ module.exports = Debuglet;
  * @event 'started' once the startup tasks are completed
  * @event 'registered' once successfully registered to the debug api
  * @event 'stopped' if the agent stops due to a fatal error after starting
+ * @event 'remotelyDisabled' if the debuggee is disabled by the server.
  * @constructor
  */
 function Debuglet(debug, config) {
@@ -330,6 +331,7 @@ Debuglet.prototype.scheduleRegistration_ = function(seconds) {
       if (result.debuggee.isDisabled) {
         // Server has disabled this debuggee / debug agent.
         onError(new Error('Disabled by the server'));
+        that.emit('remotelyDisabled');
         return;
       }
 

test/standalone/test-debuglet.js

@@ -215,6 +215,31 @@ describe(__filename, function() {
         {projectId: 'fake-project', credentials: fakeCredentials});
     debuglet = new Debuglet(debug, defaultConfig);
 
+    nocks.oauth2();
+    var scope = nock(API)
+      .post(REGISTER_PATH)
+      .reply(200, {
+        debuggee: {
+          id: DEBUGGEE_ID,
+          isDisabled: true
+        }
+      });
+
+    debuglet.once('remotelyDisabled', function() {
+      assert.ok(!debuglet.fetcherActive_);
+      scope.done();
+      done();
+    });
+
+    debuglet.start();
+  });
+
+  it('should retry after a isDisabled request', function(done) {
+    this.timeout(4000);
+    var debug = require('../..')(
+        {projectId: 'fake-project', credentials: fakeCredentials});
+    debuglet = new Debuglet(debug, defaultConfig);
+
     nocks.oauth2();
     var scope = nock(API)
       .post(REGISTER_PATH)
@@ -231,19 +256,19 @@ describe(__filename, function() {
         }
       });
 
+    var gotDisabled = false;
+    debuglet.once('remotelyDisabled', function() {
+      assert.ok(!debuglet.fetcherActive_);
+      gotDisabled = true;
+    });
+
     debuglet.once('registered', function(id) {
+      assert.ok(gotDisabled);
       assert.equal(id, DEBUGGEE_ID);
-      setImmediate(function() {
-        assert.ok(debuglet.fetcherActive_);
-        scope.done();
-        done();
-      });
+      scope.done();
+      done();
     });
 
-    setTimeout(function() {
-      assert.ok(!debuglet.fetcherActive_);
-    }, 1000);
-
     debuglet.start();
   });